Photovoltaic cell technology is actively being researched as a source of energy. A photovoltaic cell is a light to electricity (hereinafter, referred to as “light-electricity”) conversion device that converts a light source (e.g., sunlight) directly into electricity by using electromotive force generated by diffusion of minority carriers in a semiconductor excited by solar irradiation.
One drawback to present photovoltaic cells is their poor electrical performance. For example, silicon (Si)-based photovoltaic cells exhibit excessive light loss due to the cells' narrow light absorption band, which results in less than 30% theoretical light energy conversion efficiency.